This invention relates to newly identified polynucleotides, polypeptides encoded by such polynucleotides, the use of such polynucleotides and polypeptides, as well as the production of such polynucleotides and polypeptides. The polypeptides of the present invention have been putatively identified as a human haemopoietic maturation factor, sometimes hereinafter referred to as "HMF". The invention also relates to inhibiting the action of such polypeptides.
Various growth factors have been discovered, studied and utilized (cellular and molecular biology, edited by the Japanese Tissue Culture Association, Asakura Shoten (1987). Such cell growth factors include epidermal growth factor, platelet derived growth factor, acidic fibroblast growth factor and basic fibroblast growth factor among others. All these factors have been isolated based upon growth promotion of fibroblast cells. However, these factors have also been found to display widely ranging activity and poor specificity.
Accordingly, recent attempts have been made to search for growth factors specifically acting on functionally differentiated cells. As a result, growth factors such as keratinocyte growth factor and hepatocyte growth factor have been isolated, thus creating the possibility that these factors could be used to treat diseases vulnerable to their specific action spectra. Another growth factor which has been isolated is disclosed in European Patent Application No. 92102385.9 applied for by Takeda Chemical Industries, Ltd. disclosing a glia activating factor which has glial cell growth promoting activity, and the DNA encoding for that polypeptide.
Hematopoiesis is the production of blood cells. The major hematopoietic tissues are bone marrow, spleen, lymph nodes and thymus. Hematopoiesis in the human embryo begins in the second week of life. Bone marrow appears in the embryo in the second month, and it becomes the dominant hematopoietic organ in the latter half of gestation and throughout postnatal life. The bone marrow contains stem cells that give rise to all cells of the haemopoietic series. All of the blood cells except T-lymphocytes are produced in the marrow.